(a) Field of the Invention
The present invention relates to a container having a tubular mouth, particularly a container having a tubular mouth of small diameter, and having a shrink cap that is shrunk on the mouth and neck portion of the container, so that it is in tight sealing contact with the exterior surface of the neck of the container.
(b) Description of the Prior Art
Shrink caps that are adapted to be used to seal the mouth and neck portions of containers are well known. These caps have been utilized on various kinds of containers having tubular mouth portions because they can prevent soil from adhering to the tubular mouth portions of the containers and they also are advantageous because the mouth portions are sterilized by the heat applied at the time of effecting shrinkage of the shrink cap. These conventional shrink caps are constructed such that their entire inner surfaces are shrunk onto the tubular mouth and neck portions of containers. Thus, such caps have to be removed from the tubular mouth and neck portions by pulling on a lug attached to the end of a perforation line that extends axially on the tubular cap from the inner end thereof to the cover thereof, whereby the cap can be split at the perforation. However, when conventional shrink caps are used, in particular, on containers having a small diameter tubular mouth and neck portion, it becomes extremely difficult to tear the shrink cap off at the perforation line because of various problems, such as, it is very difficult for the user to insert a fingernail under the cap so as to tear the perforation, and when the user tries to hold and twist the perforated portion with his fingers it is hard for the fingers to grasp the cap with sufficient force and consequently the fingers slip on the cap surface, and so forth. Therefore, users are often compelled to cut the perforated line with a knife or the like in order to remove the cap.
Accordingly, when it is necessary to seal, in particular, the small diameter mouth and neck portions of containers, for example, the mouth portions of containers for drinking water or the connected body of a syrup tank or the like, people have actually endeavored to keep the mouth portions clean by putting nonshrinkable caps thereon. However, the nonshrinkable caps are troublesome because they can readily be removed from the mouth portions so as to be lost in the course of transport, and they have to be washed with water and then sterilized for re-use.